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Abstract:

A constant volume combustor device includes detonative combustion. In one
form the wave rotor of the constant volume combustor is supported by
magnetic bearings.

Claims:

1. A pressure wave apparatus, comprising:a rotatable rotor having a
plurality of passageways therethrough, said rotor having a direction of
rotation,a pair of exit ports disposed in fluid communication with said
rotor and adapted to receive fluid exiting from said plurality of
passageways, one of said pair of exit ports is a combusted gas exit port
for passing a substantially combusted gas from said plurality of
passageways and the other of said pair of exit ports is a buffer gas exit
port for passing a buffer gas from said plurality of passageways;a pair
of inlet ports disposed in fluid communication with said rotor and
adapted to introduce fluid to said plurality of passageways, one of said
pair of inlet ports is a working fluid inlet port for passing a working
fluid into said plurality of passageways and the other of said pair of
inlet ports is a buffer gas inlet port for receiving the buffer gas from
said buffer gas exit port and passing the buffer gas into said plurality
of passageways, said buffer gas exit port is adjacent to and sequentially
prior to said buffer gas inlet port; anda fuel deliverer adapted to
deliver a fuel within said buffer gas exit port adjacent the rotatable
rotor, wherein said fuel deliverer delivers fuel into a first portion of
said buffer gas exit port and not into a second portion of said buffer
gas exit port.

2. The pressure wave apparatus of claim 1, wherein said second portion
includes a leading portion of said buffer gas exit port.

3. The pressure wave apparatus of claim 2, wherein said leading portion is
the initial about fifteen percent of said buffer gas inlet port.

4. The pressure wave apparatus of claim 1, wherein said second portion
includes a leading portion of said buffer gas inlet port and a last
portion of said buffer gas inlet port.

5. The pressure wave apparatus of claim 4, wherein said leading portion is
defined by the initial about fifteen percent of said buffer gas inlet
port and said last portion is defined by the last about ten percent of
said buffer gas inlet port.

6. The pressure wave apparatus of claim 1, wherein said fuel deliverer
includes a plurality of fuel delivery devices spaced across said buffer
gas inlet port, and wherein at least a portion of said plurality of fuel
delivery devices are controllable to selectively deliver fuel.

7. The pressure wave apparatus of claim 1, which further includes a
passageway between said buffer gas exit port and said buffer gas inlet
port, and wherein said passageway is adapted to deliver the buffer gas
from said buffer gas exit port to said buffer gas inlet port in said
direction of rotation.

8. The pressure wave apparatus of claim 1, wherein the fuel and the
working fluid is detonated within said plurality of passageways.

9. The pressure wave apparatus of claim 1, wherein said second portion is
defined by a leading portion of said buffer gas inlet port and a last
portion of said buffer gas inlet port;wherein said fuel deliverer
includes a plurality of fuel delivery devices spaced across said buffer
gas inlet port and adapted to deliver fuel into the buffer gas flowing
through said first portion; andwherein the fuel and the working fluid
within at least one of said plurality of passageways is detonated.

10. The pressure wave apparatus of claim 9, wherein the buffer gas is
formed by compressing a portion of the working fluid within said
plurality of passageways;which further includes an igniter disposed in
communication with the fuel and working fluid within said at least one of
said plurality of passageways, andwherein said igniter being operable to
initiate the detonation of the fuel and working fluid within said at
least one of said plurality of passageways.

11. The pressure wave apparatus of claim 10, wherein said rotor having a
first end and an opposite second end;wherein said buffer gas exit port
and said pair of inlet ports are located adjacent said first end, and
said combusted gas exit port is located adjacent said second end;
andwherein said buffer gas inlet port is adjacent to and sequentially
prior to said working fluid inlet port.

12. A method, comprising:(a) rotating a wave rotor having a passageway
with a first end and a second end;(b) introducing a quantity of working
fluid into a passageway through the first end of the passageway;(c)
delivering a quantity of fuel into the passageway through the first end
of the passageway;(d) burning the fuel within the passageway and creating
a combusted gas;(e) compressing a portion of the working fluid within the
passageway to define a buffer gas;(f) discharging a first portion of the
buffer gas from the passageway through the first end of the
passageway;(g) discharging a portion of the combusted gas from the
passageway through the second end of the passageway;(h) parking a second
portion of the buffer gas within the passageway at the first end; and(i)
routing the first portion of the buffer gas from said discharging back
into the passageway through the first end of the passageway.

13. The method of claim 12, wherein at least a portion of said rotating is
accomplished by an independent drive operatively coupled with the wave
rotor.

14. The method of claim 12, wherein said parking facilitates balancing of
the fluid flow into and out of the passageway.

15. The method of claim 12, wherein the wave rotor having a plurality of
passageways, and which further includes repeating acts (a)-(i) for each
of said plurality of passageways.

[0003]The present invention relates generally to a constant volume
combustion device including detonative combustion. More specifically, one
form of the present invention is a combustion unit having a high pressure
rise, a near time-steady inflow and outflow, while being self cooled. The
constant volume combustor has properties of pulse detonation and wave
rotor technologies. Although the present invention was developed for use
as a combustor within a gas turbine engine, certain applications may be
outside of this field.

[0004]One of the next big challenges in the area of commercial and
military flight is the improvement in fuel economy as flight speeds
increase well into the supersonic range. In order to address fuel
consumption goals there will be continued engineering advancements in
compressor and turbine aerodynamics, higher temperature materials,
improved cooling schemes, and the utilization of lightweight materials.
It is recognized that the engineering and scientific community should
continue to develop greater efficiency for engine components, however
more revolutionary change may be required to meet the anticipated future
demands for gas turbine engines.

[0005]The present application is directed to more revolutionary change
through a combustion apparatus utilizing pulsed detonation and wave rotor
technologies. Since the 1940's wave rotors have been studied by engineers
and scientists and thought of as particularly suitable for a propulsion
system. A wave rotor is generally thought of as a generic term and
describes a class of machines utilizing transient internal fluid flow to
efficiently accomplish a desired flow process. Wave rotors depend on wave
phenomena as the basis of their operation, and these wave phenomena have
the potential to be exploited in novel propulsion systems, which include
benefits such as higher specific power and lower specific fuel
consumption. Pulse detonation engines have been researched as a
replacement for rockets and as an alternative propulsion system in gas
turbine engines. However, a significant drawback with pulse detonation
has been the unsteady flow produced due to the sequencing of detonations
to produce thrust or combustion. This unsteady flow is envisioned to
result in a multiplicity of mechanical and aerodynamic based challenges.

[0006]There are a variety of wave rotor devices that have been conceived
of over the years. However, until the present invention the potential for
wave rotor and pule detonation technologies has not been realized. The
present invention harnesses the potential of wave rotor and pulse
detonation technology in a novel and unobvious way.

SUMMARY OF THE INVENTION

[0007]One form of the present invention contemplates a pressure wave
apparatus, comprising: a rotatable rotor having a plurality of
passageways therethrough, the rotor having a direction of rotation; a
pair of exit ports disposed in fluid communication with the rotor and
adapted to receive fluid exiting from the plurality of passageways, one
of the pair of exit ports is a combusted gas exit port for passing a
substantially combusted gas from the plurality of passageways and the
other of the pair of exit ports is a buffer gas exit port for passing a
buffer gas from the plurality of passageways; a pair of inlet ports
disposed in fluid communication with the rotor and adapted to introduce
fluid to the plurality of passageways, one of the pair of inlet ports is
a working fluid inlet port for passing a working fluid into the plurality
of passageways and the other of the pair of inlet ports is a buffer gas
inlet port for receiving the buffer gas from the buffer gas exit port and
passing the buffer gas into the plurality of passageways, the buffer gas
exit port is adjacent to and sequentially prior to the buffer gas inlet
port; and, a fuel deliverer adapted to deliver a fuel within the buffer
gas exit port adjacent the rotatable rotor, wherein the fuel deliverer
delivers fuel into a first portion of the buffer gas exit port and not
into a second portion of the buffer gas exit port.

[0008]Another form of the present invention contemplates a method,
comprising: rotating a wave rotor having a passageway with a first end
and a second end; introducing a quantity of working fluid into the
passageway through the first end of the passageway; delivering a quantity
of fuel into the passageway through the first end of the passageway;
burning the fuel within the passageway and creating a combusted gas;
compressing a portion of the working fluid within the passageway to
define a buffer gas; discharging a first portion of the buffer gas from
the passageway through the first end of the passageway; discharging a
portion of the combusted gas from the passageway through the second end
of the passageway; parking a second portion of the buffer gas within the
passageway proximate the first end; and, routing the first portion of the
buffer gas from the discharging back into the passageway through the
first end of the passageway.

[0009]Yet another form of the present invention contemplates a method for
starting a gas turbine engine. The method, comprising: providing an
engine including a compressor, a combustor including a wave rotor having
a plurality of passageways and a turbine; rotating the wave rotor within
the combustor; fueling, at least a portion of the plurality of
passageways; combusting the fuel within the plurality of passageways to
form a flow of exhaust gas; discharging at least a portion of the exhaust
gas from the wave rotor and delivering to a bladed rotor within the
turbine; rotating the bladed rotor within the turbine with the exhaust
gas from the discharging; and, the above acts to bring the compressor and
turbine up to an operating condition.

[0010]Yet another form of the present invention contemplates an apparatus,
comprising: a compressor for increasing the pressure of a working fluid
passing therethrough, the compressor having a compressor discharge; a
constant volume combustor in fluid communication with the compressor
discharge, the constant volume combustor including a rotatable wave rotor
and a fuel deliverer, the wave rotor including a plurality of cells for
receiving at least a portion of the working fluid from the compressor
discharge and a fuel from the fuel deliverer that undergoes combustion
within the cells to produce an exhaust gas flow; a turbine in fluid
communication with the exhaust flow from the constant volume combustor;
and an active electromagnetic bearing operable to support the wave rotor.

[0011]One object of the present invention is to provide a unique constant
volume combustor.

[0012]Related objects and advantages of the present invention will be
apparent from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a schematic representation of a propulsion system
comprising a compressor, a pulsed combustion engine wave rotor, a
turbine, a nozzle and an output power shaft.

[0014]FIG. 2 is a partially exploded view of one embodiment of a pulsed
combustion engine wave rotor comprising a portion of FIG. 1.

[0015]FIG. 3 is a space-time (wave) diagram for one embodiment of a pulsed
detonation engine wave rotor of the present invention wherein the
high-pressure energy transfer gas outlet port and the exhaust gas
to-turbine port are on the same end of the device.

[0016]FIG. 4 is a schematic representation of a pulsed combustion engine
wave rotor intended to be used as a direct thrust-producing propulsion
system without conventional turbomachinery components.

[0017]FIG. 5 is a schematic representation of another embodiment of a
pulsed combustion engine wave rotor intended to be used as a direct
thrust-producing propulsion system without conventional turbomachinery
components.

[0018]FIG. 6 is a schematic representation of an alternate embodiment of a
propulsion system comprising a compressor, a pulsed combustion engine
wave rotor, a turbine, a nozzle and an output power shaft.

[0019]FIG. 7 is a partially exploded view of one embodiment of a pulsed
combustion engine wave rotor comprising a portion of FIG. 6.

[0020]FIG. 8 is a space-time (wave) diagram for an alternate embodiment of
a pulsed detonation engine wave rotor wherein the high-pressure energy
transfer gas outlet port and the combustion gas exit port are on opposite
ends of the device.

[0021]FIG. 9 is a schematic representation of a pulsed combustion engine
wave rotor intended to be used as a direct thrust-producing propulsion
system without conventional turbomachinery components.

[0022]FIG. 10 is a schematic representation of another embodiment of a
pulsed combustion engine wave rotor intended to be used as a direct
thrust-producing propulsion system without conventional turbomachinery
components.

[0023]FIG. 11 is a partially exploded view of another embodiment of a
pulsed combustion engine wave rotor comprising stationary fluid flow
passageways between rotatable endplates having inlet and outlet ports.

[0024]FIG. 12 is a space-time (wave) diagram for an alternate embodiment
of a pulsed detonation engine wave rotor wherein the fuel distribution
entering the wave rotor inlet port is non-uniform across the port.

[0025]FIG. 13 is a space-time (wave) diagram for an alternate embodiment
of a pulsed detonation engine wave rotor wherein a quantity of working
fluid without fuel is parked within the passageway to facilitate mass
flow balancing.

[0026]FIG. 14 is a space-time (wave) diagram for an alternate embodiment
of a pulsed detonation engine wave rotor wherein the fuel distribution
entering the wave rotor inlet port is non-uniform across the port and a
quantity of the working fluid without fuel is parked within the
passageway to facilitate mass flow balancing.

[0027]FIG. 15 is a space-time (wave) diagram for an alternate embodiment
of a pulsed detonation engine wave rotor wherein the wave rotor high
pressure energy transfer gas and buffer gas outlet port and gas re-entry
and inlet port are adjacent and not separated by a mechanical divider.

[0028]FIG. 16 is a space-time (wave) diagram for an another alternate
embodiment of a pulsed detonation engine wave rotor wherein the wave
rotor high pressure energy transfer gas and buffer gas outlet port and
gas re-entry and inlet port are adjacent and not separated by a
mechanical divider.

[0029]FIG. 17 is a partially exploded illustrative view of one embodiment
of a constant volume combustor comprising one form of the present
invention.

[0030]FIG. 18 is an illustrative sectional view of a gas turbine engine
including a constant volume combustor comprising one form of the present
invention.

[0031]FIG. 18a is an illustrative view of a seal comprising a portion of
one form of the present invention.

[0032]FIG. 18b is an illustrative sectional view of a seal comprising a
portion of one form of the present invention.

[0033]FIG. 18c is an illustrative sectional view of a seal comprising a
portion of one form of the present invention.

[0034]FIG. 19 is an enlarged view of the constant volume combustor of FIG.
18.

[0035]FIG. 20 is an enlarged view of a radial mount comprising a portion
of the constant volume combustor of FIG. 19.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036]For the purpose of promoting an understanding of the principles of
the invention, reference will now be made to the embodiments illustrated
in the drawings and specific language will be used to describe the same.
It will nevertheless be understood that no limitation of the scope of the
invention is thereby intended. Any alterations and further modifications
in the described embodiments, and any further applications of the
principles of the invention as described herein are contemplated as would
normally occur to one skilled in the art to which the invention relates.

[0037]With reference to FIG. 1, there is illustrated a schematic
representation of a propulsion system 20 which includes a compressor 21,
a pulsed combustion wave rotor 22, a turbine 23, a nozzle 32, and an
output power shaft 26. The compressor 21 delivers a precompressed working
fluid to the pulsed combustion wave rotor device 22. Wave rotor device 22
has occurring within its passageways the combustion of a fuel and air
mixture, and thereafter the combusted gases are delivered to the turbine
23. The working fluid that is precompressed by the compressor 21 and
delivered to the wave rotor device 22 is selected from a group including
oxygen, nitrogen, carbon dioxide, helium or a mixture thereof, and more
preferably is air. In one embodiment the pulsed combustion wave rotor
device 22 replaces the compressor diffuser and combustor of a
conventional gas turbine engine. The present invention contemplates both
a pulsed detonation combustion process and a pulsed deflagration
combustion process. While the present invention will generally be
described in terms of a pulsed detonation combustion process, it also
contemplates a pulsed deflagration combustion process.

[0038]In one embodiment the components of the propulsion system 20 have
been integrated together to produce an aircraft flight propulsion engine
capable of producing either shaft power or direct thrust or both. The
term aircraft is generic and includes helicopters, airplanes, missiles,
unmanned space devices and other substantially similar devices. It is
important to realize that there are multitudes of ways in which the
propulsion engine components can be linked together. Additional
compressors and turbines could be added with inter-coolers connected
between the compressors and reheat combustion chambers could be added
between the turbines. The propulsion system of the present invention is
suited to be used for industrial applications, such as but not limited to
pumping sets for gas or oil transmission lines, electricity generation
and naval propulsion. Further, the propulsion system of the present
invention is also suitable to be used for ground vehicular propulsion
requiring the use of shaft power such as automobiles and trucks.

[0039]With reference to FIGS. 1-3, further aspects of the propulsion
system 20 will be described. Compressor 21 is operable to increase the
pressure of the working fluid between the compressor inlet 24 and the
compressor outlet 25. The increase in working fluid pressure is
represented by a pressure ratio (pressure at outlet/pressure at inlet)
and the working fluid is delivered to a first wave rotor inlet port 42.
The first wave rotor inlet port 42 generally defines a working fluid
inlet port and is not intended to be limited to an inlet port that is
coupled to the outlet of a conventional turbomachinery component. A
second wave rotor inlet port 43 is referred to as a buffer gas inlet
port, and is located adjacent to and sequentially prior to the first wave
rotor inlet port 42. Wave rotor inlet ports 42 and 43 form an inlet port
sequence, and multiple inlet port sequences can be integrated into a
waver rotor device. In one preferred embodiment there are two inlet port
sequences disposed along the circumference of the wave rotor device.

[0040]Wave rotor device 22 has an outlet port sequence that includes an
outlet port 45 and a buffer gas outlet port 44. The outlet port 45
generally defines a combusted gas outlet port and is not intended to be
limited to an outlet port that is coupled to a turbine. In the preferred
embodiment of propulsion system 20 the outlet port 45 is defined as
to-turbine outlet port 45. The to-turbine outlet port 45 in propulsion
system 20 allows the combusted gases to exit the wave rotor device 22 and
pass to the turbine 23. Compressed buffer gas exits the buffer gas outlet
port 44 and is reintroduced into the rotor passageways 41 through the
second wave rotor inlet port 43. In one embodiment the buffer gas outlet
port 44 and the second wave rotor inlet port 43 are connected in fluid
communication by a duct. In one form the duct between the outlet port 44
and outlet port 43 is integral with the wave rotor device 22 and passes
through the interior of rotor 40. In another form the duct passes through
the center of shaft 48. In another form of the present invention the duct
is physically external to the wave rotor device 22.

[0041]The reintroduced compressed buffer gas does work on the remaining
combusted gases within the rotor passageways 41 and causes the pressure
in region 70 to remain at an elevated level. The relatively high energy
flow of combusted gases from the to-turbine port 45 is maintained in
region 74 by the reintroduction of the high pressure buffer gas entering
through the second wave rotor inlet port 43. The flow of the high
pressure buffer gas from buffer gas outlet port 44 to the second wave
rotor inlet port 43 is illustrated schematically by arrow 13 in FIG. 3.
In one form of the present invention a portion of the high pressure
buffer gas exiting through outlet port 44 can be used as a source of
turbine cooling fluid. More specifically, in certain forms of a
propulsion system of the present invention the pressure of the gas stream
going to the turbine 23 through exit port 45 is higher than the pressure
of the working fluid at the compressor discharge 25. Therefore, the
requirement for higher pressure cooling fluid can be met by taking a
portion of the high pressure buffer gas exiting port 44 and delivering to
the appropriate location(s) within the turbine.

[0042]Wave rotor outlet ports 44 and 45 form the outlet port sequence, and
multiple outlet port sequences can be integrated into a waver rotor
device. In one preferred embodiment there are two outlet port sequences
disposed along the circumference of the wave rotor device. The inlet port
sequence and the outlet port sequence are combined with the rotatable
rotor to form a pulsed combustion wave rotor engine. Routing of the
compressed buffer gas from the buffer gas outlet port 44 into the wave
rotor passageways 41 via port 43 provides for: high pressure flow issuing
generally uniformly from the to-turbine outlet port 45; and/or, a cooling
effect delivered rapidly and in a prolonged fashion to the rotor walls
defining the rotor passageways 41 following the combustion process;
and/or, a reduction and smoothing of pressure in the inlet port 42
thereby aiding in the rapid and substantially uniform drawing in of
working fluid from the compressor 21.

[0043]Combusted gasses exiting through the to-turbine outlet port 45 pass
to the turbine 23 where shaft power is produced to power the compressor
21. Additional power may be produced to be used in the form of output
shaft power. Further, combusted gas leaves the turbine 23 and enters the
nozzle 32 where thrust is produced. The construction and details related
to the utilization of a nozzle to produce thrust will not be described
herein as it is believed known to one of ordinary skill in the art of
engine design.

[0044]Referring to FIG. 2, there is illustrated a partially exploded view
of one embodiment of the wave rotor device 22. Wave rotor device 22
comprises a rotor 40 that is rotatable about a centerline X and passes a
plurality of fluid passageways 41 by a plurality of inlet ports 42, 43
and outlet ports 44, 45 that are formed in end plates 46 and 47.
Preferably, the rotor is cylindrical, however other geometric shapes are
contemplated herein. In one embodiment the end plates 46 and 47 are
coupled to stationary ducted passages between the compressor 21 and the
turbine 23. The pluralities of fluid passageways 41 are positioned about
the circumference of the wave rotor device 22.

[0045]In one form the rotation of the rotor 40 is accomplished through a
conventional rotational device. In another form the gas turbine 23 can be
used as the means to cause rotation of the wave rotor 40. In another
embodiment the wave rotor is a self-turning, freewheeling design; wherein
freewheeling indicates no independent drive means are required. In one
form the freewheeling design is contemplated with angling and/or curving
of the rotor passageways. In another form the freewheeling design is
contemplated to be driven by the angling of the inlet duct 42a so as to
allow the incoming fluid flow to impart angular momentum to the rotor 40.
In yet another form the freewheeling design is contemplated to be driven
by angling of the inlet duct 43a so as to allow the incoming fluid flow
to impart angular momentum to the rotor. Further, it is contemplated that
the inlet ducts 42a and 43a can both be angled, one of the inlet ducts is
angled or neither is angled. The use of curved or angled rotor
passageways within the rotor and/or by imparting momentum to the rotor
through one of the inlet flow streams, the wave rotor may produce useful
shaft power. This work can be used for purposes such as but not limited
to, driving an upstream compressor, powering engine accessories (fuel
pump, electrical power generator, engine hydraulics) and/or to provide
engine output shaft power. The types of rotational devices and methods
for causing rotation of the rotor 40 is not intended to be limited herein
and include other methods and devices for causing rotation of the rotor
40 as occur to one of ordinary skill in the art. One form of the present
invention contemplates rotational speeds of the rotor within a range of
about 1,000 to about 100,000 revolutions per minute, and more preferably
about 10,000 revolutions per minute. However, the present invention is
not intended to be limited to these rotational speeds unless specifically
stated herein.

[0046]The wave rotor/cell rotor 40 is fixedly coupled to a shaft 48 that
is rotatable on a pair of bearings (not illustrated). In one form of the
present invention the wave rotor/cell rotor rotates about the centerline
X in the direction of arrow Z. While the present invention has been
described based upon rotation in the direction of arrow Z, a system
having the appropriate modifications to rotate in the opposite direction
is contemplated herein. The direction Z may be concurrent with or counter
to the rotational direction of the gas turbine engine rotors. In one
embodiment the plurality of circumferentially spaced passageways 41
extend along the length of the wave rotor device 22 parallel to the
centerline X and are formed between an outer wall member 49 and an inner
wall member 50. The plurality of passageways 41 define a peripheral
annulus 51 wherein adjacent passageways share a common wall member 52
that connects between the outer wall member 49 and the inner wall member
50 so as to separate the fluid flow within each of the passageways. In an
alternate embodiment each of the plurality of circumferentially spaced
passageways are non-parallel to the centerline, but are placed on a cone
having differing radii at the opposite ends of the rotor. In another
embodiment, each of the plurality of circumferentially spaced passageways
are placed on a surface of smoothly varying radial placement first toward
lower radius and then toward larger radius over their axial extent. In
yet another embodiment, a dividing wall member divides each of the
plurality of circumferentially spaced passageways, and in one form is
located at a substantially mid-radial position of the passageway. In yet
another embodiment, each of the plurality of circumferentially spaced
passages form a helical rather than straight axial passageway.

[0047]The pair of wave rotor end plates 46 and 47 are fixedly positioned
very closely adjacent the rotor 40 so as to control the passage of
working fluid into and out of the plurality of passageways 41 as the
rotor 40 rotates. End plates 46 and 47 are designed to be disposed in a
sealing arrangement with the rotor 40 in order to minimize the leakage of
fluid between the plurality of passageways 41 and the end plates. In an
alternate embodiment auxiliary seals are included between the end plates
and the rotor to enhance sealing efficiency. Seal types, such as but not
limited to, labyrinth, gland or sliding seals are contemplated herein,
however the application of seals to a wave rotor is believed known to one
of skill in the art.

[0048]With reference to FIG. 3, there is illustrated a space-time (wave)
diagram for a pulsed detonation wave rotor engine. A pulsed detonation
combustion process is a substantially constant volume combustion process.
The pulsed detonation engine wave rotor described with the assistance of
FIG. 3 has: the high pressure energy transfer gas outlet port 44 and the
to-turbine outlet port 45 located on the same end of the device; and the
high pressure energy transfer gas inlet port 43 and the from-compressor
inlet port 42 on the same end of the device. In one form of the present
invention there is defined a two port wave rotor cycle including one
fluid flow inlet port and one fluid flow outlet port and having a high
pressure buffer gas transfer recirculation loop that may be considered
internal to the wave rotor device. The high pressure energy transfer
inlet port 43 is prior to and adjacent the from-compressor inlet port 42.
Arrow Q indicates the direction of rotation of the rotor 40. It can be
observed that upon the rotation of rotor 40, each of the plurality of
passageways 41 are sequentially brought into registration with the inlet
ports 42, 43 and the outlet ports 44, 45 and the path of a typical charge
of fluid is along the respective passageway 41. The wave diagram for the
purpose of description may be started at any point, however for
convenience the description is started at 60 wherein the low-pressure
working fluid is admitted from the compressor. The concept of low
pressure should not be understood in an absolute manner, it is only low
in comparison with the rest of the pressure levels of gas within the
pulsed detonation engine wave rotor.

[0049]The low-pressure portion 60 of the wave rotor engine receives a
supply of low-pressure working fluid from compressor 21. The working
fluid enters passageways 41 upon the from-compressor inlet port 42 being
aligned with the respective passageways 41. In one embodiment fuel is
introduced into the low-pressure portion 60 by: stationary continuously
operated spray nozzles (liquid) 61 or supply tubes (gas) 61 located
within the inlet duct 42a leading to the from-compressor inlet port 42;
or, into region 62 by intermittently actuated spray nozzles (liquid) 61'
or supply tubes (gas) 61' located within the rotor; or, into region 62 by
spray nozzles (liquid) 61'' or supply tubes (gas) 61'' located within the
rotor endplate 46. Separating region 60 and 62 is a pressure wave 73
originating from the closure of the to-turbine outlet port 45. In this
way, a region 62 exists at one end of the rotor and the region has a fuel
content such that the mixture of fuel and working fluid is combustable.
The fuel air mixture in one end of the rotor, regions 60 and 62, is thus
separated from hot residual combustion gas within regions 68 and 69 by
the buffer gas entering the rotor through port 43 and traveling through
regions 70, 71, 72 and 64. In this way undesirable pre-ignition of the
fuel air mixture of regions 60 and 62 is inhibited.

[0050]A detonation is initiated from an end portion of the rotor 40
adjacent the region 62 and a detonation wave 63 travels through the fuel
air mixture within the region 62 toward the opposite end of the rotor
containing a working-fluid-without-fuel region 64. In one form of the
present invention the detonation is initiated by a detonation initiator
80 such as but not limited to a high energy spark discharge device.
However, in an alternate form of the present invention the detonation is
initiated as an auto-detonation process and does not include a detonation
initiator. The detonation wave 63 travels along the length of the
passageway and ceases with the absence of fuel at the gas interface 65.
Thereafter, a pressure wave 66 travels into the
working-fluid-without-fuel region 64 of the passageway and compresses
this working fluid to define a high-pressure buffer/energy transfer gas
within region 67. The concept of high pressure should not be understood
in an absolute manner, it is only high in comparison with the rest of the
pressure level of gas within the pulsed detonation engine wave rotor.

[0051]In one embodiment the high pressure buffer/energy transfer gas is a
non-vitiated working fluid. In another embodiment the high pressure
buffer/energy transfer gas is comprised of working fluid having
experienced the combustion of fuel (vitiated) regardless of what other
compression or expansion process have taken place after the combustion.
Working fluid of this type would generally be characterized as having a
portion of the oxygen depleted, the products of combustion present and
the associated entropy increase remaining relative to the non-combusted
working fluid starting from the same initial state and undergoing the
same post combustion processes. An incomplete mixing can take place
between the vitiated and non-vitiated gas portions adjoining each other
in the passageway and thus realize a mixture of the two which thus
comprises the high pressure buffer/energy transfer gas.

[0052]The high pressure buffer/energy transfer gas within region 67 exits
the wave rotor device 22 through the buffer gas outlet port 44. The
combustion gases within the region 68 exit the wave rotor through the
to-turbine outlet port 45. Expansion of the combusted gas prior to
entering the turbine results in a lower turbine inlet temperature without
reducing the effective peak cycle temperature. As the combusted gas exits
the outlet port 45, the expansion process continues within the passageway
41 of the rotor and travels toward the opposite end of the passageway. As
the expansion arrives at the end of the passage, the pressure of the gas
within the region 69 at the end of the rotor opposite the to-turbine
outlet port 45 declines. The wave rotor inlet port 43 opens and allows
the flow of the high pressure buffer/energy transfer working fluid into
the rotor at region 70 and causes the recompression of a portion of the
combustion gases within the rotor. In one embodiment, the admission of
gas via port 43 can be accomplished by a shock wave. However, in another
embodiment the admission is accomplished without a shock wave. The flow
of the high pressure buffer gas adds energy to the exhaust process of the
combustion gas and allows the expansion of the combusted gas to be
accomplished in a controlled uniform energy process in one form of the
invention. Thus, in one form the introduction of the high pressure
buffer/energy transfer gas is adapted to maintain the high velocity flow
of combusted gases exiting the wave rotor until substantially all of the
combusted gas within the rotor is exhausted.

[0053]In one embodiment, the wave rotor inlet port 43, which allows the
introduction of the high-pressure buffer/energy transfer gas, closes
before the to-turbine outlet port 45 is closed. The closing of the wave
rotor inlet port 43 causes an expansion process to occur within the high
pressure buffer/energy transfer air within region 71 and lowers the
pressure of the gas and creates a region 72. Following the creation of
this lowered pressure gas region 72, a passageway 41 is in registration
with port 42 and gas flowing within port 42 enters the passageway 41
creating region 60. The strong and compact nature of the expansion
process in region 71 causes a beneficially large pressure difference
between the pressure in port 45 and the pressure in port 42. In one
embodiment the pressure of the gas delivered to the turbine 23 is higher
than the pressure delivered from the compressor 21 and hence the power
output of the engine enhanced and/or the quantity of fuel required to
generate power in the turbine is reduced. The term enhanced and reduced
are in reference to an engine utilizing a combustion device of common
practice, having constant or lowering pressure, located between the
compressor and turbine in the place of the present invention. The
expansion process 71 occurs within the buffer/energy transfer gas and
allows substantially all of the combustion gases of region 68 to exit the
rotor leaving the lowest pressure region of the rotor consisting
essentially of expanded buffer/energy transfer gas. The to-turbine outlet
port 45 is closed as the expansion in region 71 reaches the exit end of
the passageway. In one form of the present invention as illustrated in
region 75 a portion of the high-pressure buffer/energy transfer gas exits
through the outlet port 45. This gas acts to insulate the duct walls 45a
from the hot combusted gas within region 74 of the duct 45b. In an
alternate embodiment the high pressure buffer/energy transfer gas is not
directed to insulate and cool the duct walls 45a. The pressure in region
72 has been lowered, and the from-compressor inlet port 42 allows
pre-compressed low-pressure air to enter the rotor passageway in the
region 60 having the lowered pressure. The entering motion of the
precompressed low-pressure air through port 42 is stopped by the arrival
of a pressure wave 73 originating from the exit end of the rotor and
traveling toward the inlet end. The pressure wave 73 originated from the
closure of the to-turbine outlet port 45. The design and construction of
the wave rotor is such that the arrival of pressure wave 73 corresponds
with the closing of the from-compressor inlet port 42.

[0054]With reference to FIG. 4, there is illustrated schematically an
alternate embodiment of a propulsion system 30. In one embodiment the
propulsion system 30 includes a fluid inlet 31, a pulsed combustion
detonation engine wave rotor 22 and nozzle 32. The wave rotor device 22
is identical to the wave rotor described in propulsion system 20 and like
feature number will be utilized to describe like features. In one form
propulsion system 30 is adapted to produce thrust without incorporation
of conventional turbomachinery components. In one embodiment the
combustion gases exiting the wave rotor are directed through the nozzle
32 to produce motive power. The working fluid passing through inlet 31 is
conveyed through the first wave rotor inlet port 42 and into the wave
rotor device 22. High pressure buffer gas is discharged through wave
rotor outlet port 44 and passes back into the wave rotor device through
wave rotor inlet port 43. The relatively high energy flow of combusted
gases flows out of outlet port 45 and exits nozzle 32.

[0055]With reference to FIG. 5, there is illustrated schematically an
alternate embodiment of a rocket type propulsion system 100. In one
embodiment, the propulsion system 100 includes an oxidizer and working
gas storage tank 101, a pulsed combustion detonation engine wave rotor 22
and nozzle 32. The wave rotor device 22 is identical to the wave rotor
device discussed previously for propulsion system 20 and like feature
numbers will be utilized to describe like features. In one form
propulsion system 100 is adapted to produce thrust without incorporation
of conventional turbomachinery components. The first wave rotor inlet
port 42 is in fluid communication with the oxidizer and working gas
storage tank 100 and receives a quantity of working fluid therefrom. High
pressure buffer gas is discharged through the wave rotor outlet port 44
and passes back into the wave rotor device through wave rotor inlet port
43. The relatively high energy flow of combusted gases pass out of the
outlet port 45 and exits nozzle 32 to produce motive power.

[0056]A few additional alternate embodiments (not illustrated)
contemplated herein will be described in comparison to the embodiment of
FIG. 4. The use of like feature numbers is intended to represent like
features. One of the alternate embodiments is a propulsion system
including a turbomachine type compressor placed immediately ahead of the
wave rotor 22 and adapted to supply a compressed fluid to inlet 42. The
turbomachine type compressor is driven by shaft power derived from the
wave rotor 22. Another of the alternate embodiments includes a
conventional turbine placed downstream of the wave rotor 22 and adapted
to be supplied with the gas exiting port 45. The second type of alternate
embodiment does not include a nozzle and delivers only engine output
shaft power. A third embodiment contemplated herein is similar to the
embodiment of FIG. 1, but the nozzle 32 has been removed and is utilized
for delivering output shaft power. The prior list of alternate
embodiments is not intended to be limiting to the types of alternate
embodiments contemplated herein.

[0057]With reference to FIG. 6, there is illustrated a schematic
representation of an alternate embodiment of propulsion system 200 which
includes compressor 21, a pulsed combustion wave rotor 220, a turbine 23,
a nozzle 32 and an output power shaft 26. The propulsion system 200 is
substantially similar to the propulsion system 20 and like features
numbers will be utilized to describe like elements. More specifically,
the propulsion system 200 is substantially similar to the propulsion
system 20 and the details relating to system 200 will focus on the
alternative pulsed detonation engine wave rotor 220.

[0058]With reference to FIGS. 6-8, further aspects of the propulsion
system 200 will be described. As discussed previously, a substantial
portion of the propulsion system 200 is identical to the propulsion
system 20 and this information will not be repeated as it has been set
forth previously. A pressurized working fluid passes through the
compressor outlet 25 and is delivered to a first wave rotor inlet port
221. A second wave rotor inlet port 222 is referred to as a buffer gas
inlet port, and is located adjacent to and sequentially prior to the
first wave rotor inlet port 221. Wave rotor inlet ports 221 and 222 form
an inlet port sequence, and multiple inlet port sequences can be
integrated into a wave rotor device. In one preferred embodiment there
are two inlet port sequences disposed along the circumference of the wave
rotor device 220.

[0059]Wave rotor device 220 has an outlet port sequence that includes an
outlet port 223 and a buffer gas outlet port 224. In one embodiment of
propulsion system 200 the outlet port 223 is defined as a to-turbine
outlet port 223. The to-turbine outlet port 223 of propulsion system 200
allows the combusted gases to exit the wave rotor device 220 and pass to
the turbine 223. Compressed buffer gas exits the buffer gas outlet port
224 and is reintroduced into the rotor passageways 41 through the second
wave rotor inlet port 222. In one embodiment, the buffer gas outlet port
224 and the second wave rotor inlet port 222 are connected in fluid
communication by a duct. In a further alternate embodiment, the duct
functions as a high pressure buffer gas reservoir and/or is connected to
an auxiliary reservoir which is designed and constructed to hold a
quantity of high pressure buffer gas. This reintroduced buffer gas does
work on the remaining combusted gases within the rotor passageways 41 and
causes the pressure in region 225 to remain at an elevated level. The
relatively high energy flow of combusted gases from the to-turbine port
223 is maintained in region 226 by the reintroduction of the high
pressure buffer gas entering through the second wave rotor inlet port
222. The flow of the high pressure buffer gas from buffer gas outlet port
224 to the second wave rotor inlet port 222 is illustrated schematically
by arrows C in FIG. 8.

[0060]Wave rotor outlet ports 223 and 224 form the outlet port sequence,
and multiple outlet port sequences can be integrated into a wave rotor
device. In one preferred embodiment, there are two outlet port sequences
disposed along the circumference of the wave rotor device. The inlet port
sequence and the outlet port sequence are combined with the rotatable
rotor to form a pulsed combustion wave rotor engine. Routing of the
compressed buffer gas from the buffer gas outlet port 224 into the wave
rotor passageways 41 provides for: high pressure flow issuing generally
uniformly from the to-turbine outlet port 223; and/or a cooling effect
delivered rapidly and in a prolonged fashion to the rotor walls defining
the rotor passageways 41 following the combustion process; and/or a
reduction and smoothing of pressure in the inlet port 221 thereby aiding
in the rapid and uniform admission of working fluid from compressor 21.

[0061]Referring to FIG. 7, there is illustrated a partially exploded view
of one embodiment of the wave rotor device 220. Wave rotor 220 comprises
a cylindrical rotor 40 that is rotatable about a centerline X and passes
a plurality of fluid passageways 41 by a plurality of ports 221, 222 and
224 formed in end plate 225 and outlet ports 223 formed in end plate 226.
In one embodiment, the end plates 225 and 226 are coupled to stationery
ducted passages between the compressor 21 and the turbine 23. The
plurality of fluid passageways 41 is positioned about the circumference
of the wave rotor device 220.

[0062]In one form a conventional rotational device accomplishes the
rotation of rotor 40. In another form the gas turbine 23 can be used as
the means to cause rotation of the wave rotor 40. In another embodiment
the wave rotor is a self-turning, freewheeling design; wherein
freewheeling indicates no independent drive means are required. In one
form, the freewheeling design is contemplated with angling and/or curving
of the rotor passageways. In another form, the freewheeling design is
contemplated to be driven by the angling of the inlet duct 221a so as to
allow the incoming fluid flow to impart angular momentum to the rotor 40.
In yet another form, the free-wheeling design is contemplated to be
driven by angling of the inlet duct 222a so as to allow the incoming
fluid flow to impart angular momentum to the rotor. Further, it is
contemplated that the inlet ducts 222a and 221a can both be angled, one
of the inlet ducts is angled or neither is angled. The use of curved or
angled rotor passageways within the rotor and/or by imparting of momentum
to the rotor through one of the inlet flow streams, the wave rotor may
produce useful shaft power.

[0063]The wave rotor/cell rotor 40 is fixedly coupled to a shaft 48 that
is rotatable on a pair of bearings (not illustrated). In one form of the
present invention, the wave rotor/cell rotor rotates about the center
line X in the direction of arrows Z. While the present invention has been
described based upon rotation in the direction of arrow Z, a system
having the appropriate modifications to rotate in the opposite direction
is contemplated herein. The direction Z may be concurrent with or counter
to the rotational direction of the gas turbine engine rotors. In one
embodiment the plurality of circumferentially spaced passageways 41
extend along the length of the wave rotor device 220 parallel to the
center line X and are formed between the outer wall member 49 and an
inner wall member 50. The plurality of passageways 41 define a peripheral
annulus 51 wherein adjacent passageways share a common wall member 52
that connects between the outer wall member 49 and the inner wall 50 so
as to separate the fluid flow within each of the passageways. In an
alternate embodiment each of the plurality of circumferentially spaced
passageways are non-parallel to the center line, but are placed on a cone
having different radii at the opposite ends of the rotor. In another
embodiment, a dividing wall member divides each of the plurality of
circumferentially spaced passageways, and in one form is located at a
substantially mid-radial position. In yet another embodiment, each of the
plurality of circumferentially spaced passageways form a helical rather
than straight passageway. Further, in another embodiment, each of the
plurality of circumferentially spaced passageways are placed on a surface
of smoothly varying radial placement first toward lower radius and then
toward larger radius over their axial extent.

[0064]The pair of wave rotor end plates 225 and 226 are fixedly positioned
very closely adjacent to rotor 40 so as to control the passage of working
fluid into and out of the plurality of passageways 41 as the rotor 40
rotates. End plates 225 and 226 are designed to be disposed in a sealing
arrangement with the rotor 40 in order to minimize the leakage of fluid
between the plurality of passageways 41 and the end plates. In an
alternate embodiment, auxiliary seals are included between the end plates
and the rotor to enhance sealing efficiency. Seal types, such as but not
limited to, labyrinth, gland or sliding seals are contemplated herein,
however, the application of seals to a wave rotor is believed known to
one of skill in the art.

[0065]With reference to FIG. 8, there is illustrated a space-time (wave)
diagram for a pulsed detonation wave rotor engine. The pulsed detonation
engine wave rotor described with the assistance of FIG. 8 has: the high
pressure energy transfer gas outlet port 224, the high pressure energy
transfer gas inlet port 222 and the from-compressor inlet port 221 on the
same end of the device; and the to-turbine outlet port 223 located on the
opposite end of the device. In one form of the present invention there is
defined a two port wave rotor cycle including one fluid flow inlet port
and one fluid flow outlet port and having a high pressure buffer gas
recirculation loop that may be considered internal to the wave rotor
device. The high pressure energy transfer inlet port 222 is prior to and
adjacent the from-compressor inlet port 221. It can be observed that upon
the rotation of rotor 40 each of the plurality of passageways 41 are
sequentially brought in registration with the inlet ports 221 and 222 and
the outlet ports 223 and 224, and the path of a typical charge of fluid
is along the respective passageways 41. The wave diagram for the purpose
of description may be started at any point, however, for convenience, the
description is started at 227 wherein the low-pressure working fluid is
admitted from the compressor. The concept of low pressure should not be
understood in absolute manner, it is only low in comparison with the rest
of the pressure level of gas within the pulsed detonation engine wave
rotor.

[0066]The low pressure portion 227 of the wave rotor engine receives a
supply of low-pressure working fluid from compressor 21. The working
fluid enters passageways 41 upon the from-compressor inlet port 221 being
aligned with the respective passageways 41. In one embodiment fuel is
introduced into the region 225 by: stationery continuously operated spray
nozzles (liquid) 227 or supply tubes (gas) 227 located within the duct
222a leading to the high pressure energy transfer gas inlet port 222; or,
into region 228 by intermittently actuated spray nozzles (liquid) 227' or
supply tubes (gas) 227' located within the rotor; or, into region 228 by
spray nozzles (liquid) 227'' or supply tubes (gas) 227'' located within
the rotor end plate 226. Region 228 exists at the end of the rotor and
the region has a fuel content such that the mixture of fuel and working
fluid is combustable.

[0067]A detonation is initiated from an end portion of the wave rotor 40
adjacent the region 228 and a detonation wave 232 travels through the
fuel-working-fluid air mixture within the region 228 toward the opposite
end of the rotor containing a working-fluid-without-fuel region 230. In
one form of the present invention, the detonation is initiated by a
detonation initiator 233, such as but not limited to a high energy spark
discharge device. However, in an alternate form of the present invention
the detonation is initiated by an auto-detonation process and does not
include a detonation initiator. The detonation wave 232 travels along the
length of the passageway and ceases with the absence of fuel at the gas
interface 234. Thereafter, a pressure wave 235 travels into the
working-fluid-without-fuel region 230 of the passageway and compresses
this working fluid to define a high-pressure buffer/energy transfer gas
within region 236. The concept of high pressure should not be understood
in an absolute manner, it is only high in comparison with the rest of the
pressure level of gas within the pulsed detonation engine wave rotor.

[0068]The high pressure buffer/energy transfer gas within region 236 exits
the wave rotor device 220 through the buffer gas outlet port 224. The
combusted gases within the region 237 exits the wave rotor through the
to-turbine outlet port 223. Expansion of the combusted gas prior to
entering the turbine results in a lower turbine inlet temperature without
reducing the effective peak cycle temperature. As the combusted gas exits
the outlet port 223, the expansion process continues within the
passageways 41 of the rotor and travels toward the opposite end of the
passageway. As the expansion arrives at the end of the passage, the
pressure of the gas within the region 238 at the end of the rotor
opposite the to-turbine outlet port 223 declines. The wave rotor inlet
port 222 opens and allows the flow of the high pressure buffer/energy
transfer working fluid into the rotor at region 225 and causes the
recompression of a portion of the combusted gases within the rotor. The
admission of gas via port 222 can be accomplished by a shock wave. The
flow of the high pressure buffer gas adds energy to the exhaust process
of the combustion gas and allows the expansion of the combusted gas to be
accomplished in a controlled, uniform energy process in one form of the
invention. Thus, in one form the introduction of the high pressure
buffer/energy transfer gas is adapted to maintain the high velocity flow
of combusted gases exiting the wave rotor until substantially all of the
combusted gas within the rotor is exhausted.

[0069]In one embodiment, the wave rotor inlet port 222, which allows the
introduction of the high pressure buffer/energy transfer gas, closes
before the to-turbine outlet port 223 is closed. The closing of the wave
rotor inlet port 222 causes an expansion process to occur within the high
pressure buffer/energy transfer air within region 240 and lowers the
pressure of the gas and creates a region 241. This expansion process
occurs within the buffer/energy transfer gas and allows this gas to
preferentially remain within the rotor at the lowest pressure region of
the rotor. The to-turbine outlet port 223 is closed as the expansion in
region 240 reaches the exit end of the passageway. In one form of the
present invention as illustrated in region 242, a portion of the high
pressure buffer/energy transfer gas exits through the outlet port 223.
This exiting buffer/energy transfer gas functions to insulate the duct
wall 223a from the hot combusted gas within region 226 of the duct 223b.
The pressure in region 241 has been lowered and the from-compressor inlet
port 221 allows pre-compressed low pressure working fluid to enter the
rotor passageways in the region 227 having the lowered pressure. The
entering motion of the pre-compressed low-pressure working fluid through
port 221 is stopped by the arrival of pressure wave 231 originating from
the exit end of the rotor and traveling toward the inlet end. The
pressure wave 231 originated from the closure of the to-turbine outlet
port 223. The design and construction of the wave rotor is such that the
arrival of the pressure wave 231 corresponds with the closing of the
from-compressor inlet port 221.

[0070]With reference to FIG. 9, there is illustrated schematically an
alternate embodiment of a propulsion system 300. In one embodiment the
propulsion system 300 includes a fluid inlet 31, a pulsed combustion
detonation engine wave rotor 220 and a nozzle 32. The wave rotor device
220 is identical to the wave rotor described in propulsion system 200 and
like feature numbers will be utilized to indicate like features. In one
form propulsion system 30 is adapted to produce thrust without
incorporation of conventional turbomachinery components. The working
fluid passing through the inlet 31 is conveyed through the first wave
rotor inlet port 221 and into the wave rotor 220. High pressure buffer
gas is discharged through wave rotor outlet port 224 and passes back into
the wave rotor device through wave rotor inlet port 222. The relatively
high energy flow of combusted gases flows out of the outlet port 223 and
exits through nozzle 32 to produce motive power.

[0071]With reference to FIG. 10, there is illustrated schematically an
alternate embodiment of a rocket type propulsion system 400. In one
embodiment, the propulsion system 400 includes an oxidizer and working
gas storage tank 101, a pulsed combustion detonation engine wave rotor
220 and a nozzle 32. The wave rotor device 220 is identical to the wave
rotor described in propulsion system 200 and like feature numbers will be
utilized to indicate like features. In one form propulsion system 400 is
adapted to produce thrust without incorporation of conventional
turbomachinery components. The first wave rotor inlet port 221 is in
fluid communication with the oxidizer and working gas storage tank 101
and receives a quantity of working fluid therefrom. High pressure buffer
gas is discharged through the wave rotor outlet port 224 and passes back
into the wave rotor device through wave rotor inlet port 222. The
relatively high energy flow of combusted gases pass out of the outlet
port 223 and exits nozzle 32 to produce motive power.

[0072]A few of the additional alternate embodiments (not illustrated)
contemplated herein will be described in comparison to the embodiment of
FIG. 9. The utilization of like feature numbers is intended to represent
like features. One of the alternate embodiments includes a turbomachine
type compressor placed immediately ahead of the wave rotor 220 and
adapted to supply a compressed fluid to inlet 221. The turbomachine type
compressor is driven by shaft power derived from the wave rotor 220. A
second alternate embodiment includes a conventional turbine placed
downstream of the wave rotor 220 and adapted to be supplied with the gas
exiting port 223. The second type of alternate embodiment does not
include a nozzle and delivers only engine output shaft power.

[0073]The present invention is also applicable to a mechanical device
wherein the plurality of fluid flow passageways are stationery, the inlet
and outlet ports are rotatable, and the gas flows and processes occurring
within the fluid flow passageways are substantially similar to those
described previously in this document. Referring to FIG. 11, there is
illustrated a partially exploded view of one embodiment of the wave rotor
device 320. The description of a wave rotor device having rotatable inlet
and outlet ports is not limited to the embodiment of device 320, and is
applicable to other wave rotors including but not limited to the
embodiments associated with FIGS. 1-5 and 9-10. The utilization of like
feature numbers will be utilized to describe like features. In one form
wave rotor device 320 comprises a stationary portion 340 centered about a
centerline X and having a plurality of fluid passageways 41 positioned
between two rotatable endplates 325 and 326. The endplates 325 and 326
are rotated to pass by the fluid passageways a plurality of inlet ports
221 and 222 and outlet ports 224 and 223. Endplates 325 and 326 are
connected to shaft 348 and form a rotatable endplate assembly. In one
embodiment a member 349 mechanically fixes the endplates 325 and 326 to
the shaft 348. Further, the endplate assembly is rotatably supported by
bearings, which are not illustrated. In one embodiment the endplates 325
and 326 are fitted adjacent to stationary ducted passages between the
compressor 21 and turbine 23. Sealing between the stationary ducts and
the rotating endplates is accomplished by methods and devices believed
known of those skilled in the art. In a preferred form the stationary
portion 340 defines a ring and the plurality of fluid passageways 41 are
positioned about the circumference of the ring.

[0074]In one form a conventional rotational device is utilized to
accomplish the rotation of the endplate assembly including endplates 325
and 326. In another form the gas turbine 23 can be used as the means to
cause rotation of the endplates 325 and 326. In another embodiment the
endplate assembly is a self-turning, freewheeling design; wherein
freewheeling indicates no independent drive means are required. In one
form the freewheeling design is contemplated with the use of an endplate
designed so as to capture a portion of the momentum energy of the fluid
exit stream of port 224 and hence provide motive force for rotation of
the endplate. In another form the freewheeling design is contemplated to
be driven by a portion of the momentum energy of the exit stream of port
223. In another form the freewheeling design is contemplated to be driven
by a portion of the momentum energy of the inlet stream of port 222. In
yet another form the freewheeling design is contemplated to be driven by
a portion of the momentum energy of the inlet stream of port 221. In all
cases a portion of the endplate port flowpath may contain features
turning the fluid stream within one or two exit endplate port flowpaths
and one or two inlet endplate port flowpaths in the tangential direction
hence converting fluid momentum energy to power to rotate the endplate.
The use of curved or angled passageways within the stationary portion 340
may aid in this process by imparting tangential momentum to the exit flow
streams which may be captured within the endplate through turning of the
fluid stream back to the axial direction. In each of these ways the
rotating endplate assembly may also provide useful shaft power beyond
that required to turn the endplate assembly. This work can be used for
purposes such as but not limited to, driving an upstream compressor,
powering engine accessories (fuel pump, electrical power generator,
engine hydraulics) and/or to provide engine output shaft power. The types
of rotational devices and methods for causing rotation of the endplate
assembly is not intended to be limited herein and include other methods
and devices for causing rotation of the endplate assembly as occur to one
of ordinary skill in the art. One form of the present invention
contemplates rotational speeds of the endplate assembly within a range of
about 1,000 to about 100,000 revolutions per minute, and more preferably
about 10,000 revolutions per minute. However, the present invention is
not intended to be limited to these rotational speeds unless specifically
stated herein.

[0075]The endplates 325 and 326 are fixedly coupled to the shaft 348 that
is rotatable on a pair of bearings (not illustrated). In one form of the
present invention the endplates rotate about the centerline X in the
direction of arrow C. While the present invention has been described
based upon rotation in the direction of arrow C, a system having the
appropriate modifications to rotate in the opposite direction is
contemplated herein. The direction C may be concurrent with or counter to
the rotational direction of the gas turbine engine rotors.

[0076]The pair of rotating endplates 325 and 326 are fixedly positioned
very closely adjacent the stationary portion 340 so as to control the
passage of working fluid into and out of the plurality of passageways 41
as the endplates rotate. Endplates 325 and 326 are designed to be
disposed in a sealing arrangement with the stationary portion 340 in
order to minimize the leakage of fluid between the plurality of
passageways 41 and the endplates. In an alternate embodiment auxiliary
seals are included between the end plates and the rotor to enhance
sealing efficiency. Seal types, such as but not limited to, labrynth,
gland or sliding seals are contemplated herein, however the application
of seals to a wave rotor is believed known to one of skill in the art.

[0077]With reference to FIG. 12, there is illustrated a space-time (wave)
diagram for an alternate embodiment of a pulsed detonation engine wave
rotor. The pulsed detonation engine wave rotor is similar to the pulsed
detonation engine wave rotor described with the assistance of FIG. 8.
However, the pulsed detonation engine wave rotor described with the
assistance of FIG. 12 has the fuel distribution changed within the region
prior to high pressure energy transfer gas inlet port 222. The changing
of the fueling at the region just prior to the high pressure energy
transfer gas inlet port 222 is utilized to adjust the exit temperature of
the fluid from the pulsed detonation engine wave rotor. The fuel
adjustment can be used to tailor the fluid exit temperature to materials
utilized in the turbine downstream from the outlet and/or to alter the
quantity of power output delivered by operation of the device by altering
the exit temperature. A plurality of fuel delivery devices 400 is located
across the duct 222a prior to the high pressure energy transfer gas inlet
port 222. In one form the fuel delivery devices 400 are active elements
that can be controlled to selectively delivery fuel into the duct 222a.
In the embodiment illustrated in FIG. 12, the fuel delivery devices 400a,
400b and 400c are delivering fuel and the remaining fuel delivery devices
are not activated to deliver fuel. The quantity and location of the fuel
delivery devices in FIG. 12 is not intended to be limiting and other
quantities and locations are contemplated herein. The fuel may be
delivered in a liquid or gaseous form.

[0078]In one form of the present invention, a leading first unfueled
portion 401 of the high pressure energy transfer gas inlet port 222 is
left unfueled. The leading first unfueled portion 401 is within a range
of about two to about seventy-five percent of the inlet port 222, and in
a preferred form is about 15 percent of the inlet port 222 and the rest
of the port is fueled. In another form of the present invention, a second
last unfueled portion 402 of the high pressure energy transfer gas inlet
port 222 is left unfueled and the rest of the port 222 is fueled. The
second unfueled portion is within a range of about two to about fifty
percent and the rest of the port is fueled, and in a preferred from the
second unfueled portion is about 10 percent and the rest of the port is
unfueled. A preferred form of the present application includes a first
unfueled portion 401 and a second unfueled portion 402, and preferably
the first unfueled portion is about 15 percent and the second unfueled
portion is about 10 percent. However, other percentages for the unfueled
portions are contemplated herein.

[0079]The pulsed detonation engine wave rotor described with the
assistance of FIG. 12 has the high pressure energy transfer gas outlet
port 224, the high pressure energy transfer gas inlet port 222 and the
from-compressor inlet port 221 on the same end of the device; and the
to-turbine outlet port 223 located on the opposite end of the device. In
one form of the present invention there is defined a two port wave rotor
cycle including one fluid flow inlet port and one fluid flow outlet port
and having a high pressure buffer gas recirculation loop that may be
considered internal to the wave rotor device. The high pressure energy
transfer inlet port 222 is prior to and adjacent the from-compressor
inlet port 221. It can be observed that upon the rotation of rotor 40
each of the plurality of passageways 41 are sequentially brought in
registration with the inlet ports 221 and 222 and the outlet ports 223
and 224, and the path of a typical charge of fluid is along the
respective passageways 41. The wave diagram for the purpose of
description may be started at any point, however, for convenience, the
description is started at 227 wherein the low-pressure working fluid is
admitted from the compressor. The concept of low pressure should not be
understood in absolute manner, it is only low in comparison with the rest
of the pressure level of gas within the pulsed detonation engine wave
rotor.

[0080]The low pressure portion 227 of the wave rotor engine receives a
supply of low-pressure working fluid from compressor 21. The working
fluid enters passageways 41 upon the from-compressor inlet port 221 being
aligned with the respective passageways 41. Fuel is introduced into the
region 403 by the fuel delivery devices 400a, 400b and 400c. The region
403 is a fueled region and the regions 404 and 405 are non-fueled regions
with a non-vitiated working fluid. A portion of the region 403 exists at
the end of the rotor and this region has a fuel content such that the
mixture of fuel and working fluid is combustible.

[0081]A detonation is initiated from an end portion of the wave rotor 40
adjacent the region 228 and a detonation wave 232 travels through the
fuel-working-fluid air mixture within the region 403 toward the opposite
end of the rotor containing a working-fluid-without-fuel region 230. In
one form of the present invention, a detonation initiator 233 initiates
the detonation; such as but not limited to a high energy spark discharge
device. However, in an alternate form of the present invention the
detonation is initiated by an auto-detonation process and does not
include a detonation initiator. The detonation wave 232 travels along the
length of the passageway and ceases with the absence of fuel at the gas
interface 234. Thereafter, a pressure wave 235 travels into the
working-fluid-without-fuel region 230 of the passageway and compresses
this working fluid to define a high-pressure buffer/energy transfer gas
within region 236. The concept of high pressure should not be understood
in an absolute manner, it is only high in comparison with the rest of the
pressure level of gas within the pulsed detonation engine wave rotor.

[0082]The high pressure buffer/energy transfer gas within region 236 exits
the wave rotor device 220 through the buffer gas outlet port 224. The
combusted gases within the region 237 exits the wave rotor through the
to-turbine outlet port 223. Expansion of the combusted gas prior to
entering the turbine results in a lower turbine inlet temperature without
reducing the effective peak cycle temperature. As the combusted gas exits
the outlet port 223, the expansion process continues within the
passageways 41 of the rotor and travels toward the opposite end of the
passageway. As the expansion arrives at the end of the passage, the
pressure of the gas within the region 238 at the end of the rotor
opposite the to-turbine outlet port 223 declines. The wave rotor inlet
port 222 opens and allows the flow of the high pressure buffer/energy
transfer working fluid into the rotor at region 225 and causes the
recompression of a portion of the combusted gases within the rotor. The
admission of gas via port 222 can be accomplished by a shock wave. The
flow of the high pressure buffer gas adds energy to the exhaust process
of the combustion gas and allows the expansion of the combusted gas to be
accomplished in a controlled, uniform energy process in one form of the
invention. Thus, in one form the introduction of the high pressure
buffer/energy transfer gas is adapted to maintain the high velocity flow
of combusted gases exiting the wave rotor until substantially all of the
combusted gas within the rotor is exhausted.

[0083]In one embodiment, the wave rotor inlet port 222, which allows the
introduction of the high pressure buffer/energy transfer gas, closes
before the to-turbine outlet port 223 is closed. The closing of the wave
rotor inlet port 222 causes an expansion process to occur within the high
pressure buffer/energy transfer air within region 240 and lowers the
pressure of the gas and creates a region 404. This expansion process
occurs within the buffer/energy transfer gas and allows this gas to
preferentially remain within the rotor at the lowest pressure region of
the rotor. The to-turbine outlet port 223 is closed as the expansion in
region 240 reaches the exit end of the passageway. As illustrated in
region 242, the portion of the high pressure buffer/energy transfer gas
in region 405 exits through the outlet port 223. This exiting
buffer/energy transfer gas functions to insulate the duct wall 223a from
the hot combusted gas within region 226 of the duct 223b. The pressure in
region 404 has been lowered and the from-compressor inlet port 221 allows
pre-compressed low pressure working fluid to enter the rotor passageways
in the region 227 having the lowered pressure. The entering motion of the
pre-compressed low-pressure working fluid through port 221 is stopped by
the arrival of pressure wave 231 originating from the exit end of the
rotor and traveling toward the inlet end. The pressure wave 231
originated from the closure of the to-turbine outlet port 223. The design
and construction of the wave rotor is such that the arrival of the
pressure wave 231 corresponds with the closing of the from-compressor
inlet port 221.

[0084]With reference to FIG. 13, there is illustrated a space-time (wave)
diagram for a pulsed detonation engine wave rotor that utilizes a cycle
that is substantially similar to the cycle set forth in FIG. 8. However,
the pulsed detonation engine wave rotor described with the assistance of
FIG. 13 has the location of the gas interface 600 in a different location
to facilitate mass flow balancing within the system. The mass flow
balancing is accommodated by parking a quantity of the high-pressure
buffer/energy transfer gas from region 236 in region 601. The energy of
compression imparted previously to the gas of region 601 by compression
wave 235 is released to the flow of gas moving to exhaust port 226 by the
arrival of expansion wave 238 and acts to expel it to the exhaust port in
an energetic manner. The parked gas in region 601, being non-vitiated and
does not gain fuel. This gas 601 thus separates the vitiated combustion
gas of elevated temperature from the stationary end wall 401 hence
avoiding heating of wall 401. Similarly, the gas of region 601 separates
the vitiated combustion gas of region 237 and the gas with fuel added
entering from port 222. Gas in region 601 moves to pass into region 242
and thereby insulates surface 223a from the combustion gas of region 226.
The pulsed detonation engine wave rotor described with the assistance of
FIG. 13 has the high pressure energy transfer gas outlet port 224, the
high pressure energy transfer gas inlet port 222 and the from-compressor
inlet port 221 on the same end of the device; and the to-turbine outlet
port 223 located on the opposite end of the device. In one form of the
present invention there is defined a two port wave rotor cycle including
one fluid flow inlet port and one fluid flow outlet port and having a
high pressure buffer gas recirculation loop that may be considered
internal to the wave rotor device. The high pressure energy transfer
inlet port 222 is prior to and adjacent the from-compressor inlet port
221. It can be observed that upon the rotation of rotor 40 each of the
plurality of passageways 41 are sequentially brought in registration with
the inlet ports 221 and 222 and the outlet ports 223 and 224, and the
path of a typical charge of fluid is along the respective passageways 41.
The wave diagram for the purpose of description may be started at any
point, however, for convenience, the description is started at 227
wherein the low-pressure working fluid is admitted from the compressor.
The concept of low pressure should not be understood in absolute manner,
it is only low in comparison with the rest of the pressure level of gas
within the pulsed detonation engine wave rotor.

[0085]The low pressure portion 227 of the wave rotor engine receives a
supply of low-pressure working fluid from compressor 21. The working
fluid enters passageways 41 upon the from-compressor inlet port 221 being
aligned with the respective passageways 41. In one embodiment fuel is
introduced into the region 225 by: stationery continuously operated spray
nozzles (liquid) 227 or supply tubes (gas) 227 located within the duct
222a leading to the high pressure energy transfer gas inlet port 222; or,
into region 228 by intermittently actuated spray nozzles (liquid) 227' or
supply tubes (gas) 227' located within the rotor; or, into region 228 by
spray nozzles (liquid) 227'' or supply tubes (gas) 227'' located within
the rotor end plate 226. Region 228 exists at the end of the rotor and
the region has a fuel content such that the mixture of fuel and working
fluid is combustible.

[0086]A detonation is initiated from an end portion of the wave rotor 40
adjacent the region 228 and a detonation wave 232 travels through the
fuel-working-fluid air mixture within the region 228 toward the opposite
end of the rotor containing a working-fluid-without-fuel region 230. In
one form of the present invention, a detonation initiator 233 initiates
the detonation; such as but not limited to a high energy spark discharge
device. However, in an alternate form of the present invention the
detonation is initiated by an auto-detonation process and does not
include a detonation initiator. The detonation wave 232 travels along the
length of the passageway and ceases with the absence of fuel at the gas
interface 234. Thereafter, a pressure wave 235 travels into the
working-fluid-without-fuel region 230 of the passageway and compresses
this working fluid to define a high-pressure buffer/energy transfer gas
within region 236. The concept of high pressure should not be understood
in an absolute manner, it is only high in comparison with the rest of the
pressure level of gas within the pulsed detonation engine wave rotor.

[0087]A portion of the high pressure buffer/energy transfer gas within
region 236 exits the wave rotor device 220 through the buffer gas outlet
port 224 and a portion is maintained within the wave rotor device 220 in
region 601. As discussed previously, the energy of the compression
imparted previously to the gas of region 601 by compression wave 235 is
released to the flow of gas moving to exhaust port 236 by the arrival of
expansion wave 238 and acts to expel it to the exhaust port. This parked
gas within the region 601 separates the vitiated combusted gas of
elevated temperatures from the end wall 401. Similarly, the gas within
region 601 separates the vitiated combustion gas of region 237 and the
gas with fuel added entering from port 222. The gas within region 601
passes into region 245 and insulates surface 233a from the combustor gas
within region 226

[0088]The combusted gases within the region 237 exits the wave rotor
through the to-turbine outlet port 223. Expansion of the combusted gas
prior to entering the turbine results in a lower turbine inlet
temperature without reducing the effective peak cycle temperature. As the
combusted gas exits the outlet port 223, the expansion process continues
within the passageways 41 of the rotor and travels toward the opposite
end of the passageway. As the expansion arrives at the end of the
passage, the pressure of the gas within the region 238 at the end of the
rotor opposite the to-turbine outlet port 223 declines. The wave rotor
inlet port 222 opens and allows the flow of the high pressure
buffer/energy transfer working fluid into the rotor at region 225 and
causes the recompression of a portion of the combusted gases and the gas
from region 601 within the rotor. The admission of gas via port 222 can
be accomplished by a shock wave. The flow of the high pressure buffer gas
adds energy to the exhaust process of the combustion gas and allows the
expansion of the combusted gas to be accomplished in a controlled,
uniform energy process in one form of the invention. Thus, in one form
the introduction of the high pressure buffer/energy transfer gas is
adapted to maintain the high velocity flow of combusted gases exiting the
wave rotor until substantially all of the combusted gas within the rotor
is exhausted.

[0089]In one embodiment, the wave rotor inlet port 222, which allows the
introduction of the high pressure buffer/energy transfer gas, closes
before the to-turbine outlet port 223 is closed. The closing of the wave
rotor inlet port 222 causes an expansion process to occur within the high
pressure buffer/energy transfer air within region 240 and lowers the
pressure of the gas and creates a region 240. This expansion process
occurs within the buffer/energy transfer gas and allows this gas to
preferentially remain within the rotor at the lowest pressure region of
the rotor. The to-turbine outlet port 223 is closed as the expansion in
region 240 reaches the exit end of the passageway. In one form of the
present invention as illustrated in region 242, a portion of the high
pressure buffer/energy transfer gas exits through the outlet port 223.
This exiting buffer/energy transfer gas functions to insulate the duct
wall 223a from the hot combusted gas within region 226 of the duct 223b.
The pressure in region 241 has been lowered and the from-compressor inlet
port 221 allows pre-compressed low pressure working fluid to enter the
rotor passageways in the region 227 having the lowered pressure. The
entering motion of the pre-compressed low-pressure working fluid through
port 221 is stopped by the arrival of pressure wave 231 originating, from
the exit end of the rotor and traveling toward the inlet end. The
pressure wave 231 originated from the closure of the to-turbine outlet
port 223. The design and construction of the wave rotor is such that the
arrival of the pressure wave 231 corresponds with the closing of the
from-compressor inlet port 221.

[0090]With reference to FIG. 14, there is illustrated a space-time (wave)
diagram for an alternate embodiment of a pulsed detonation engine wave
rotor. The pulsed detonation engine wave rotor cycle includes the fuel
distribution system of FIG. 12 and the mass flow balancing of FIG. 13
that is accommodated by parking a quantity of the high-pressure
buffer/energy transfer gas from region 236 in region 601. The combination
of the two embodiments results in the embodiment of FIG. 15 operating
within a select range of exhaust port 223 gas temperatures generally
higher or lower than that of the other embodiments depending on fuel heat
capacity and limits on fuel to air combustibility ratios. The fueled
portion of the gas in region 403 is made to arrive at the exit end of a
passage at the end of port 223 an hence bring fueled gas into region 228.

[0091]With reference to FIGS. 15 and 16 there are illustrated space-time
(wave) diagrams for alternative embodiments of pulsed detonation engine
wave rotors. Each of the respective systems includes a high pressure
energy transfer gas inlet port 222 and a high pressure energy transfer
gas outlet port 224 that are not separated by a mechanical divider. It
should be understood herein that the embodiments are applicable broadly
to the systems and aspects disclosed within this application. The high
pressure inflow and outflow occurring adjacent one another in two ports
that are not separated by a mechanical divider. Referring to FIG. 15,
there is illustrated the compressed gas of region 236 flowing into port
224. As any passageway of the rotor 40 proceeds due to rotation in
direction Q, the arrival of expansion waves 238 slows the gas entry into
port 224. There exists at some point D, a condition at which the gas
entry into port 224 ceases due to an equilibrium of pressures in region
236 and port 224. At point D, port 224 is essentially closed due to gas
action rather than the presence of a physical wall 401 as in the
embodiment of FIG. 14. As rotation of rotor 40 continues and arrival of
expansion wave 238 continues to reduce the pressure, region 225 is
reached where gas issues from port 222a. Fuel is admitted utilizing the
identical method of 227 as described embodiment with reference to FIG. 8.

[0092]Referring to FIG. 16, there is illustrated an embodiment of the
present invention in which, for reasons of gas mass balance, the
combustion gas of region 237 reach or very nearly reach point D as
described with the assistance of the embodiment of FIG. 15. The relative
positioning of the interface between regions 236 and 237 and the
interface between regions 225 and 237 in the embodiments of FIGS. 15 and
16 respectively is in the existence of a parked gas region 601 in FIG.
15. This unfueled portion of gas results in the layer of relatively cool
gas of region 405 which proceeds to exit port 223. This gas within region
405 functions in the same manner described in the embodiment of FIG. 14.

[0093]With reference to FIG. 17, there is illustrated an exploded view of
one embodiment of the constant volume combustor 200. Constant volume
combustor 200 includes a transition duct 201 for providing fluid
communication pathway with the compressor and/or other inlet of the
engine. The constant volume combustor 200 further includes an endplate
202 with a plurality of ports 220, and an endplate 203 with a plurality
of exit ports 221 and detonation initiation devices 204. Fluid passes
through the plurality of exit ports 221 into a transition duct 206
including fluid flow passageways passages 207. Further, the constant
volume combustor 200 includes a plurality of buffer ducts 208 that
deliver the buffer air to different locations within the rotor 205. The
reader should appreciate that the delivery of air through the buffer
ducts 208 is in the direction of rotation. Each of the buffer ducts 208
may includes a fuel delivery mechanism. The constant volume combustor has
been described with the aid of FIG. 17, however the present application
contemplates other constant volume combustors capable of utilizing the
cycles described previously in this application. In a preferred form, the
constant volume combustor 200 has detonative combustion occurring
therein.

[0094]With reference to FIG. 18, there is illustrated a cross-sectional
view of a gas turbine engine with the constant volume combustor 200
integrated therein. The term gas turbine engine is intended to be
interpreted broadly and the present inventions are contemplated for
utilization with virtually all typical forms of gas turbine engines
unless specifically provided to the contrary. The constant volume
combustor 200 receives a working fluid from the primary flowpath of the
compressor section 210 through transition duct 201. In one form of the
present invention the working fluid discharged from the compressor has a
temperature of about 1212° F., however other working fluid
temperatures are contemplated herein. The working fluid is delivered to
the constant volume combustor 200 and a first portion of the working
fluid is utilized in the ensuing combustion within the wave rotor
passages 225. A second portion of the working fluid is extracted through
port 212 and is utilized as cooling fluid for the low pressure turbine
airfoils and to provide secondary cooling airflow to the low pressure
turbine seals.

[0095]The constant volume combustor 200 raises the pressure of working
fluid from the primary flowpath 211 above the pressure from the
compressor discharge and therefore the compressor discharge working fluid
is too low in pressure to be utilized for high pressure turbine cooling.
In one form of the present invention, the constant volume combustor 200
raises the pressure of the working fluid from the primary flowpath 211
about 20%. The present invention contemplates pressure rises within the
range of about 10% to about 50%; however, other pressure rises are
contemplated herein. The turbine section 215 includes a first stage
nozzle 216a having a plurality of nozzle guide vanes 216. In one form of
the present invention the nozzle guide vanes 216 are transpiration
cooled, therefore the cooling media delivered to the respective nozzle
guide vanes 216 must be at a pressure higher than the working fluid flow
exiting the constant volume combustor 200. In one form of the present
invention in order to provide cooling media to the plurality of guide
vanes 216, some of the working fluid from the constant volume combustor
return ducts 208 is bled off, and ducted around the constant volume
combustor to the nozzle guide vane 216. In one form the working fluid
flows through a passageway defined between the constant volume combustor
rotor 205 and the outer combustor case 235. The working fluid follows the
flowpath as indicated by arrows A to cool the guide vanes 216. The
working fluid bled from the constant volume combustor return duct is
relatively high in pressure and above the pressure of the discharged
working fluid from the constant volume combustor discharge; making it an
excellent source for cooling fluid. A portion of the working fluid from
the constant volume combustor return duct passes directly through the
first stage nozzle 216a and is used to cool blades 220 of the high
pressure turbine. However, the present application is applicable to
propulsion systems having nozzle guide vanes that are not actively
cooled.

[0096]In one form of the present invention the constant volume combustor
200 is located within the combustor case 235 and has an inner vent cavity
226 and an outer vent cavity 227 adjacent thereto. These cavities form a
relatively lower pressure sink to enable one form of the constant volume
combustor endplates 202 and 203 to function. In one embodiment of the
present invention, each of the endplates 202 and 203 float
hydrostatically on a cushion of working fluid and are located a small
distance from the rotating face of the rotor 205. In one form of the
present invention the small distance is within a range of about 0.0005
inches to about 0.0015 inches. With reference to FIGS. 18a-b, there is
schematically illustrated the operation of the sealing plates 202 and
203. FIG. 18a represents a circumferential view at the ports 220. FIG.
18b represents a circumferential view between the ports 220. The sealing
plate illustrated is the forward sealing plate and has a face 700 that
sees the pressure from the constant volume combustor rotor passage 200
and the vent cavity 226. A quantity of the high pressure working fluid
208a bled from the constant volume combustor return duct 208 is supplied
into the sealing plate and is discharged through a plurality of ports 701
into the gap adjacent the rotating rotor end. The discharged working
fluid from the plurality of ports 701 allows the seal plate to float
hydrostatically on a thin film of working fluid and remain a finite small
gap from the end of the rotating rotor. The aft seal plate is free to
move axially in a stationary structure in order to seek it own location.
At the other end of the rotor there is located a substantially similar
seal plate that functions in substantially the same fashion as the aft
sealing plate. However, in a preferred form of the present application,
this seal plate is fixed to the outer combustor case.

[0097]With reference to FIG. 18c, there is schematically illustrated
various features of the sealing plate 202 and by extension the plate 203.
The sealing plate illustrated is the forward sealing plate in very close
proximity to the rotor 205. A quantity of the high pressure working fluid
208a bled from the constant volume combustor return duct 208 is supplied
into the sealing plate and is discharged through the aforementioned ports
701 not shown here, into the very small spacing between the seal plate
202 and the adjacent rotating rotor end. The discharged working fluid
208a from duct 208 allows the seal plate to float hydrostatically on a
thin film of working fluid and remain at high pressure in the finite
small space. In this embodiment, confinement of this high pressure gas is
enhanced by the presence of labyrinth knife seal of design knowledgeable
by one schooled in this art placed at the inner and outer diameter of the
rotor. Also in this embodiment, the seal plate is confined in its axial
movement relative to the stationary structure 201 by "C" seal and spring
500 in order to balance the forces on the seal plate 202 and prevent
bleed air 208a from duct 208 from entering unrestrained into port 220. An
anti-rotation pin 505 is fixed to 201 and mated to a slot in plate 202 to
avoid rotation of plate 202. Similarly in this embodiment at the other
end of the rotor there is located a substantially similar seal plate that
functions in substantially the same fashion as the forward sealing plate.

[0098]A fan duct 705 has a quantity of fan duct working fluid flowing
therethrough. A portion of the fan duct flow is bled off and used to cool
selected components within the engine. In one form the fan duct flow is
utilized to cool magnetic bearings located within the engine. Feature
numbers 710, 711, 712 and 713 sets forth examples of the magnetic
bearings. In one embodiment of the present invention the constant volume
combustor rotor 205 is supported by and rotates on radial magnetic
bearings 710 and 711. With reference to FIG. 19, the radial magnetic
bearings 710 and 711 each have a stator portion 720 coupled to a member
721 that is connected to the mechanical housing 725 and a rotor portion
731 that is coupled with an attachment structure 742 of the constant
volume combustor rotor 205. In a preferred form the magnetic bearings 710
and 711 are active electromagnetic bearings that are controlled by a
controller. In one form of the present invention there is a significant
thermal gradient between the constant volume combustor rotor 205 and the
magnetic bearings 720. Presently, magnetic bearings are generally limited
to applications having environmental temperatures of up to about
800° F. In one form, the present invention substantially isolates
in a thermal sense the magnetic bearing from the rotor 205. More
specifically, a thermal conduction limiting structure is utilized to
couple the constant volume combustor rotor 205 with the magnetic
bearings.

[0099]With reference to FIG. 20, there is illustrated one form of the
thermal conduction limiting structure including a pin joint 730 of the
plurality of pin joints coupling the rotor 205 with the supporting
structure 731. The pin joint 730 includes a radial pin 732 mechanically
connecting the structure 760 of the rotor 205 with the supporting
structure 742 and the pin joint limiting the conductive heat transfer
path between the wave rotor 205 and the supporting structure 731. The
limited conductive heat transfer path associated with the radial pin 732
is due to the reduced flowpath for energy by conduction and is one means
to thermally isolate the rotor 205 from the radial magnetic bearings. The
present application further contemplates a system utilizing other forms
of bearings and other coupling structures for the bearings, whether the
bearings are magnetic bearings or some other type of bearing also needing
thermal isolation as known to one of skill in the art.

[0100]The constant volume combustor rotor 205 could be designed as a free
wheeling structure or one that is driven during at least portions of its
operating cycle. One embodiment of the present invention contemplates the
utilization of the radial magnetic bearings and a conventional
electrically driven starter motor located with the magnetic bearings 720
supporting the rotor, said motor functioning to cause rotation of the
rotor. Further, the present invention contemplates conventional means to
drive the rotor 205 during start up or at other engine operating
conditions. One system contemplates a conventional starter operatively
coupled to the rotor 205 to provide the initial rotation necessary to
start the constant volume combustor.

[0101]The present application contemplates that, in the starting of the
engine including the constant volume combustor, the constant volume
combustor would be started before the rest of the machine and hence act
to start the rest of the machine. The rotor 205 of the constant volume
combustor would be brought up to a predetermined speed and fuel added and
upon ignition the constant volume combustor would discharge working fluid
that impinges on the high pressure turbine which starts the high pressure
turbine rotor, the output of which then starts the low pressure rotor
spinning. The spinning high pressure and low pressure turbines would
continue as the rest of the machine is started. Further, in another
embodiment the constant volume combustor includes a starter and a
generator. The starter and generator are controllable to provide the
ability to modify the rotational speed of the constant volume combustor
rotor. The starter could be engaged to increase the speed and add energy
during desired operating parameters, while the generator could be engaged
to decrease the speed and extract energy during desired operating
parameters.

[0102]While the invention has been illustrated and described in detail in
the drawings and foregoing description, the same is to be considered as
illustrative and not restrictive in character, it being understood that
only the preferred embodiment has been shown and described and that all
changes and modifications that come within the spirit of the invention
are desired to be protected. It should be understood that while the use
of the word preferable, preferably or preferred in the description above
indicates that the feature so described may be more desirable, it
nonetheless may not be necessary and embodiments lacking the same may be
contemplated as within the scope of the invention, that scope being
defined only by the claims that follow. In reading the claims it is
intended that when words such as "a," "an," "at least one," "at least a
portion" are used there is no intention to limit the claim to only one
item unless specifically stated to the contrary in the claim. Further,
when the language "at least a portion" and/or "a portion" is used the
item may include a portion and/or the entire item unless specifically
stated to the contrary.